[Federal Register Volume 62, Number 114 (Friday, June 13, 1997)]
[Proposed Rules]
[Pages 32412-32423]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 97-15457]


      

[[Page 32411]]

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Part III





Department of Transportation





_______________________________________________________________________



Federal Aviation Administration



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14 CFR Parts 25, 121, and 135



Revised Standards for Cargo or Baggage Compartments in Transport 
Category Airplanes; Proposed Rule

  Federal Register / Vol. 62, No. 114 / Friday, June 13, 1997 / 
Proposed Rules  

[[Page 32412]]



DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Parts 25, 121 and 135

[Docket No. 28937, Notice No. 97-10]
RIN 2120-AG42


Revised Standards for Cargo or Baggage Compartments in Transport 
Category Airplanes

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of proposed rulemaking (NPRM).

-----------------------------------------------------------------------

SUMMARY: This notice of proposed rulemaking proposes to upgrade the 
fire safety standards for cargo or baggage compartments in certain 
transport category airplanes by eliminating Class D compartments as an 
option for future type certification. Compartments that could no longer 
be designated as Class D would have to meet the standards for Class C 
or Class E compartments, as applicable. The Class D compartments in 
certain transport category airplanes manufactured under existing type 
certificates and used in passenger service would have to meet the fire 
detection and suppression standards for Class C Compartments by early 
2001 for use in air carrier, commuter, on-demand, or most other 
commercial service. The Class D compartments in certain transport 
category airplanes manufactured under existing type certificates and 
used only for the carriage of cargo would also have to meet such 
standards or the detection standards for Class E compartments by that 
date for such service. These improved standards are needed to increase 
protection from possible in-flight fires.

DATE: Comments must be received on or before September 11, 1997.

ADDRESSES: Comments on this proposal may be mailed in duplicate to: 
Federal Aviation Administration, Office of the Chief Counsel, 
Attention: Rules Docket (AGC-200), Docket No. 28937, 800 Independence 
Avenue SW, Washington, DC 20591, or delivered in person to Room 915G at 
the same address. Comments delivered must be marked: Docket 28937. 
Comments may also be submitted electronically to 9-n prm-
[email protected]. Comments may be inspected in Room 915G weekdays, 
except Federal holidays, between 8:30 a.m. and 5:00 p.m. In addition, 
the FAA is maintaining an information docket of comments in the 
Transport Airplane Directorate (ANM-100), Federal Aviation 
Administration, 1601 Lind Avenue SW, Renton, Washington 98055-4056. 
Comments in the information docket may be inspected in the Transport 
Airplane Directorate weekdays, except Federal holidays, between 7:30 
a.m. and 4:00 p.m.

FOR FURTHER INFORMATION CONTACT: Gary L. Killion, Manager, Regulations 
Branch, ANM-114, Transport Airplane Directorate, Aircraft Certification 
Service, FAA, 1601 Lind Ave. S.W., Renton, Washington 98055-4056; 
telephone (425) 227-2114.

SUPPLEMENTARY INFORMATION:

Comments Invited

    Interested persons are invited to participate in the proposed 
rulemaking by submitting such written data. views, or arguments as they 
may desire. Comments relating to any environmental, energy, federalism, 
or economic impacts that might result from adoption of the proposals 
contained in this notice are also invited. Substantive comments should 
be accompanied by cost estimates. Commenters should identify the 
regulatory docket or notice number and submit comments, in triplicate, 
to the Rules Docket address specified above. All comments will be 
considered by the Administrator before action on the proposed 
rulemaking is taken. The proposals contained in this notice may be 
changed in light of the comments received. All comments will be 
available in the Rules Docket, both before and after the closing date 
for comments, for examinations by interested persons. A report 
summarizing each substantive public contact with FAA personnel 
concerning this rulemaking will be filed in the docket. Commenters 
wishing the FAA to acknowledge receipt of their comments must submit 
with those comments a self-addressed, stamped postcard on which the 
following statement is made: ``Comments to Docket No.'' The postcard 
will be dated and time stamped and returned to the commenter.

Availability of NPRM

    An electronic copy of this document may be downloaded using a 
modern an suitable communications software from the FAA regulations 
section of the Fedworld electronic bulletin board service (telephone: 
703-321-3339), the Federal Register's electronic bulletin board service 
(202-512-1661), or the FAA's Aviation Rulemaking Advisory Committee 
Bulletin Board service (telephone 202-267-5948).
    Internet users may reach the FAA's web page at http://www.faa.gov 
or the Federal Register's web page at http://www.access.gpo.gov/
su__docs for access to recently published rulemaking documents.
    Any person may obtain a copy of this NPRM by submitting a request 
to the Federal Aviation Administration, Office of Rulemaking, ARM-1, 
800 Independence Avenue SW, Washington, DC 20591; or by calling (202) 
267-9680. Communications must identify the notice number of this NPRM. 
Persons interested in placing on a mailing list for future NPRM's 
should also request a copy of Advisory Circular No. 11-2A, Notice of 
Proposed Rulemaking Distribution system, which describes the 
application procedures.

Background

    There have been a number of fires in the cargo or baggage 
compartments of transport category airplanes in recent years, some of 
which have resulted in accidents and loss of life. Although the FAA has 
already taken action to improve the safety of these compartments by 
improving the fire-resistance of liners, the continuing occurrence of 
fires and the seriousness of the consequences of an uncontrolled fire 
have resulted in a review of the entire cargo compartment 
classification system.
    During the early post-World War II period, it was recognized that 
timely detection of a fire by a crewmember of the airplane while at his 
or her station and prompt control of the fire when detected were 
necessary for protection of the airplane from a fire originating in a 
cargo or baggage compartment. Because the requirements for detection 
and extinguishment varied depending on the type and location of the 
compartment, a classification system was established. Three classes of 
cargo or baggage compartments were initially established and defined in 
1946 (Amendment 04-1 to part 04 of the Civil Air Regulations (CAR) 
effective November 1, 1946) as follows:
    Class A--A compartment in which the presence of a fire would be 
easily discovered by a crewmember while at his or her station, and of 
which all parts are easily accessible in flight. This is typically a 
small compartment used for crew luggage, and located in the cockpit 
where a fire would be readily detected and extinguished by a 
crewmember. Due to the small size and location of the compartment, and 
the relatively brief time needed to detect and extinguish a fire, a 
liner is not required to prevent the fire from spreading to other parts 
of the airplane or protect adjacent structure.
    Class B--A compartment with a separate, approved smoke or fire

[[Page 32413]]

detection system to give warning at the pilot or flight engineer 
station and with sufficient access in flight to enable a crewmember to 
effectively reach any part of the compartment with a hand fire 
extinguisher. Smoke or fire detection systems must provide indication 
of a fire to the flightcrew. Because it has a smoke or fire detection 
system, a Class B compartment may be located in an area remote from any 
crewmember's station. Due to the potentially larger size of the 
compartment and the greater time interval likely to occur before a fire 
would be extinguished, a liner meeting the flame penetration standards 
of Sec. 25.855 and Part I of Appendix F of part 25 must be provided to 
prevent the fire from spreading to other areas of the airplane and to 
protect adjacent structure. As originally defined in 1946, there was 
also to be sufficient access to enable the crewmember to move all 
contents of a Class B compartment by hand; however, that requirement 
was subsequently deleted. Although Class B compartments are typically 
the large cargo portions of the cabins of airplanes carrying a 
combination of passengers and cargo (frequently referred to as 
``combi'' airplanes), there are also Class B compartments that are 
relatively small baggage compartments located within the pressurized 
portions of airplanes designed for executive transportation.
    Class C--As defined at the time of initial classification in 1946, 
any compartment that did not fall into either Class A or B was a Class 
C compartment. Class C compartments differ from Class B compartments 
primarily in that built-in extinguishing systems are required for 
control of fires in lieu of crewmember accessibility. As with Class B 
compartments, smoke or fire detection systems must be provided. Due to 
the use of a built-in extinguishing system and closer control of 
ventilating airflow, the distribution of extinguishing agent in a Class 
C compartment is considerably more uniform than in a Class B 
compartment. The volumes of Class C compartments in transport category 
airplanes currently used in domestic service range from approximately 
700 to 3,000 cubic feet.
    Later, two additional classes of cargo or baggage compartments were 
established and defined as follows (Amendment 4b-6 to part 4b of the 
CAR effective March 5, 1952):
    Class D--A compartment in which a fire would be completely 
contained without endangering the safety of the airplane or the 
occupants. A Class D compartment is similar to a Class C compartment in 
that both may be located in areas that are not readily accessible to a 
crewmember. As originally defined in 1952, Class D compartments were 
required to have smoke or fire detection systems; however, that 
requirement was deleted shortly thereafter. In lieu of providing smoke 
or fire detection and extinguishment, Class D compartments are designed 
to control a fire by severely restricting the supply of available 
oxygen. Because an oxygen-deprived fire might continue to smolder for 
the duration of a flight, the capability of the liner to resist flame 
penetration is especially important. A note following the definition of 
a Class D compartment stated, ``For compartments having a volume not in 
excess of 500 cubic feet, an airflow of not more than 1,500 cubic feet 
per hour is considered acceptable. For larger compartments, lesser 
airflow may be applicable.'' That note was interpreted to mean that a 
Class D compartment could not exceed 2,000 cubic feet in volume even if 
the leakage of air into the compartment was zero. The standards for 
Class D compartments were later amended (Amendment 25-60, 51 FR 18236, 
May 16, 1986) to specifically limit the volume of those compartments to 
1,000 cubic feet; however, some previously-approved airplanes in air 
carrier service have Class D compartments as large as 1,630 cubic feet. 
Other airplanes designed for executive transportation, and also used in 
on-demand service, have relatively small (15-25 cubic feet) Class D 
compartments located outside the pressurized portions of the cabin.
    Class E--A cargo compartment of an airplane used only for the 
carriage of cargo (Amendment 4b-10 to part 4b of the CAR, adopted in 
1959). A smoke or fire detection system is required. In lieu of 
providing extinguishment, means must be provided to shut off the flow 
of ventilating air to or within a class E compartment. In addition, 
procedures, such as depressurizing a pressurized airplane, are 
stipulated to minimize the amount of oxygen available in the event a 
fire occurs in a Class E compartment. Typically, a Class E compartment 
is the entire cabin of an all-cargo airplane; however, Class E 
compartments may be located in other portions of the airplane. This, of 
course, does not preclude the installation of Class A, B, C or D 
compartments in all-cargo airplanes.
    Prior to the adoption of Sec. 25.858 in 1980, fire or smoke 
detection systems that provided indication within five minutes were 
considered acceptable. In order to ensure that a fire would be detected 
in time to permit effective use of the means provided to control it, 
Sec. 25.858 was adopted at that time (Amendment 25-54, 45 FR 60173, 
September 11, 1980) to require the detection systems of Class B, C and 
E compartments to provide visual indication to the flight crew within 
one minute of the start of the fire.
    It should be noted that the overhead storage areas and certain 
other areas in the cabins of passenger-carrying airplanes are 
considered ``stowage'' compartments rather than cargo or baggage 
compartments. They are therefore not required to meet these standards.
    Although the standards for Class A, B, C or D compartments make no 
distinction between compartments used for the carriage of passengers' 
baggage and those used for cargo, most of the industry experience at 
the time they were classified was limited to the carriage of 
passengers' baggage. Furthermore, compartments seldom, if ever, 
exceeded 200 cubic feet in volume at that time.
    When first defined, Class D. compartments were envisioned to be 
small compartments, although not as small as Class A compartments, and 
were to suppress a fire by severely restricting the amount of available 
oxygen. Later, however, larger Class D compartments were installed in 
transport category airplanes, increasing both the amount of potentially 
combustible material and the available oxygen. Although there is little 
or no flow of air into a Class D compartment at the time a fire occurs, 
there is oxygen available from the air already contained in the 
compartment. In some instances, particularly when the compartment is 
larger or only partially filled, the oxygen already present in the 
compartment may be sufficient to support an intense fire long enough 
for it to penetrate the liner. Once the integrity of the liner is 
compromised, there is an unlimited flow of air into the compartment, 
resulting in an uncontrollable fire that can quickly spread throughout 
the rest of the airplane.
    An uncontrollable fire of this nature did occur in 1980 when a 
Saudi Arabian Airlines Lockheed L-1011 was destroyed shortly after 
landing. The fire, which resulted in a loss of 301 lives, was reported 
to have started in a Class D compartment. (The compartment in that 
airplane is sometimes described erroneously as a Class C compartment 
because it has smoke detection. During normal operation, the 
compartment has ventilating airflow greater than that normally 
acceptable for a Class D compartment in order to facilitate the 
carriage of live animals. When a fire is detected, the ventilating 
airflow is shut off to restrict the supply of oxygen. That compartment, 
therefore, functioned as a

[[Page 32414]]

Class D compartment insofar as that fire is concerned.) The growing 
concern over this and other reports of cargo or baggage compartment 
fires led to the adoption of Amendment 25-60. In addition to 
establishing a maximum volume of 1,000 cubic feet for Class D 
compartments, Amendment 25-60 also established new standards for liners 
with greater resistance to flame penetration for use in Class C and D 
compartments. That amendment applied to transport category airplanes 
for which an application for type certificate is made on or after June 
16, 1985. Similar, but not identical, standards were also established 
for the liners of other transport category airplanes operated under the 
provisions of parts 121 or 135 (Amendments 121-202 and 135-31, 54 FR 
7384, February 17, 1989). Operators of those airplanes were required to 
install liners that meet the new standards by March 20, 1991. Unlike 
Amendment 25-60, Amendments 121-202 and 135-31 do not establish a 
maximum volume for Class D compartments.
    A Boeing 737 operated by Gulf Air was destroyed in September 1983 
as a result of an inflight fire in a Class D compartment. The fire, 
which resulted in 112 casualties, was attributed to an incendiary 
device.
    In February 1988, a fire occurred in the Class D compartment of an 
American Airlines McDonnell Douglas MD-83. Although there was no loss 
of life, the fire severely damaged the cabin floor above the 
compartment. As a result, the FAA initiated a review of service 
experience and existing regulations, policies and procedures pertaining 
to the certification of airplanes with Class D compartments. From this 
review, it was determined that a dozen fires had occurred in Class D 
Compartments over the past two decades. The consequences of those fires 
ranged from no airplane damage and no occupant injury to complete 
destruction of the Saudi Arabian Airlines Lockheed L-1011, as discussed 
above.
    Since the time the review of Class D compartments was completed 
there have also been seven additional known instances of fires 
occurring in those compartments. Most resulted in no injuries and 
little or no damage to the airplane. The exception, insofar as injuries 
and damage are concerned, was the fire that occurred in May of 1996 in 
the Class D compartment of a McDonnell Douglas DC-9 operated by Valujet 
Airlines. Like the American Airlines MD-83 fire noted above, that fire 
involved the carriage of undeclared hazardous materials; however, 
unlike the MD-83 fire, it resulted in the destruction of the airplane 
with a loss of 110 lives. It must be noted that this undeclared 
shipment occurred in spite of existing prohibitions concerning such 
shipments.
    In the meantime, an additional potential hazard in the cargo or 
baggage compartments of passenger-carrying airplanes has been brought 
to light. Due to environmental concerns, the aerosol cans now 
manufactured for consumer use utilize a mixture of propane, butane and 
isobutane for propellants in lieu of the non-flammable gases previously 
used. Passengers are not prohibited from transporting such aerosol cans 
by the applicable hazardous materials rules, and they have become so 
widely used by the general public that a high percentage of the pieces 
of checked baggage contain at least one aerosol can. Tests conducted by 
the FAA Technical Center show that they can burst if they are in a 
burning suitcase for little more than two minutes. The tests further 
show that if the burst occurs in a non-inert atmosphere, such as that 
of a Class D compartment, there is immediate auto-ignition of the 
propellant. The accompanying explosion is of such force and intensity 
that the liner could be rendered ineffective in limiting the supply of 
oxygen to the fire. Because the liner would be damaged by the explosion 
rather than by flame penetration, the use of a liner meeting the newer 
standards of Amendment 25-60 would not provide protection from this 
hazard. With an unlimited supply of oxygen and the integrity of the 
liner compromised, there is no longer any effective means to prevent an 
uncontrollable fire from spreading to other parts of the airplane. If, 
on the other hand, the burst occurs in an inert atmosphere, such as 
that of a Class C compartment in which the extinguishing agent has been 
discharged, the propellant does not ignite and poses no further hazard. 
(As noted above, smoke or fire detectors are required to provide 
indication to the flightcrew within one minute after the start of a 
fire, allowing sufficient time in which to inert the compartment before 
aerosol cans would burst.) The results of these tests are contained in 
Report No. DOT/FAA/CT-89/32 entitled ``Fire Hazards of Aerosol Cans in 
Aircraft Cargo Compartments.'' A copy of that report has been placed in 
the docket for examination by interested persons.
    In at least one instance, a cargo or baggage compartment fire 
resulted in the plastic cap being melted from an aerosol can. 
Fortuitously, however, none of the fires experienced since aerosol cans 
with flammable propellants were introduced were of such intensity or 
proximity to result in an aerosol can being ruptured.
    It must be noted that the probability that an ignition will occur 
is primarily a function of the flammability of the material being 
carried in the compartment and the sources of ignition; however, the 
consequences of a fire, once ignition has occurred, depend greatly on 
the fire-protection features of the compartment in which it occurs. The 
FAA is aware of at least four fires that have occurred in Class C 
compartment during the past decade--a rate of occurrence somewhat 
commensurate with that of fires occurring in Class D compartments. 
(Three of those fires involved U.S. air carriers.) In marked contrast 
to the fatalities that have occurred as a result of fires originating 
in Class D compartments, the FAA is not aware of any fatality that has 
occurred as a result of a fire originating in a Class C compartment.
    On December 12, 1996, the Air Transport Association of America 
(ATA), jointed by Vice President Gore, formally announced that its 
membership would voluntarily install fire or smoke detection systems in 
Class D compartments. The ATA is a trade organization that represents 
the major US airlines. Details of the ATA plan--including an 
implementation schedule--were presented to FAA officials on January 31, 
1997. The announcement, which affects approximately 2,700 airplanes 
operated by 21 ATA members, might appear to make the detection portion 
of this rulemaking moot; however, the FAA considers the installation of 
both detection and suppression systems in these compartments to be 
essential. In any event, a number of airplanes in service with Class D 
compartments are operated by non-ATA member airlines and would not be 
subject to voluntary ATA ban.
    On May 14, 1997, the ATA announced its commitment to go forward 
with fire suppression systems as well as detection systems. At this 
time, however, the airlines have not committed to a time frame for the 
installation of such systems.

Discussion

    As noted above, some Class D compartments are much larger than 
envisioned at the time they were originally defined. As a result, they 
typically contain considerably more combustible material than 
anticipated. Although there is little or no airflow into a Class D 
compartment at the time a fire occurs, there is oxygen available

[[Page 32415]]

from the air already contained in the compartment. In some instances, 
particularly in the larger compartments or those that are only 
partially filled, this quantity of oxygen may be sufficient to support 
an intense fire long enough for it to burn through the liner. If the 
integrity of the liner is compromised, there is an unlimited flow of 
oxygen into the compartment. With the liner no longer intact and an 
unlimited flow of oxygen supporting the fire, there is no means to 
prevent it from spreading rapidly throughout the airplane. Due to the 
widespread use of aerosol cans with highly flammable propellants, there 
is now a possibility that an explosion will destroy the liner 
integrity. A fire originating in even the smallest Class D compartments 
could, therefore, become uncontrollable. In view of these possibly 
catastrophic results, part 25 would be amended to eliminate Class D 
compartments altogether. Compartments in passenger-carrying airplanes 
that could no longer be approved as Class D compartments would have to 
meet the standards of Class C compartments.
    Due to the uncertainties of the availabilities of suitable 
suppression agents, as discussed in greater detail under Halon 
Considerations below, the FAA considered the possibility of requiring 
only the installation of detection systems. Having a detection system 
would enable the flight crew to abort a takeoff if an ignition occurred 
during the brief period before the airplane became airborne. If, on the 
other hand, the fire occurred after the airplane became airborne, which 
is more likely, the fire could burn out of control before a safe 
landing could be made. In that regard, it should be noted that 301 
lives were lost in the Saudi Arabian Lockheed L-1011 fire described 
above even though the compartment did, in fact, have a detection 
system. Since the installation of detection systems alone would provide 
only a small incremental increase in safety, it is essential that both 
detection and suppression systems be provided for these compartments.
    As discussed above, Class E compartments may be installed in 
airplanes used only for the carriage of cargo. As in the case of a 
Class C compartment, a smoke or fire detection system is required for a 
Class E compartment. In lieu of providing extinguishment, as required 
for a Class C compartment, means must be provided to shut off the flow 
of ventilating air to or within a Class E compartment. In addition, 
procedures, such as depressurizing the airplane, are stipulated to 
further minimize the amount of oxygen available in the event a fire 
occurs in a Class E compartment. Compartments in all-cargo airplanes 
that could no longer be approved as Class D compartments could be shown 
to meet the standards of Class E compartments in lieu of those for 
Class C compartments. The installation of smoke or fire detection 
systems and the means provided to minimize the amount of oxygen in 
Class E compartments would provide an improvement in safety for 
compartments presently designated as Class D and installed in all-cargo 
airplanes. The benefit from that improvement in the safety of operation 
of all-cargo airplanes would be commensurate with the cost of 
converting Class D compartments to Class E compartments.
    Part 25 presently contains an inconsistency between the terminology 
used in Sec. 25.857 and that of Sec. 25.858. The former refers to a 
``smoke detector or fire detector system'' for Class B, C or E 
compartments while the latter refers to compartments with ``fire 
detection provisions.'' Smoke detectors are, of course, a form of fire 
detectors since the purpose of installing a smoke detection system is 
to detect a fire. Nevertheless, the use of different terminology in the 
two sections may cause confusion. For consistency with Sec. 25.857, 
Sec. 25.858 would be amended to refer to ``smoke or fire detection 
provisions.'' This change would place no additional burden on any 
person since the intent of Sec. 25.858 would remain unchanged.
    It is also noted that the term ``fire extinguishing system'' 
appearing in Sec. 25.857(c) in regard to Class C compartments is 
actually a misnomer in that the system is not required to extinguish a 
fire in its entirety, but rather to suppress it until it can be 
completely extinguished by ground personnel following a safe landing. 
Although the intent of the term is well-understood, consideration was 
given to replacing it with ``fire suppression system'' for technical 
accuracy. While the latter would be more accurate, it appears that 
changing the terminology at this time could actually create confusion 
and, therefore, be counter-productive. The term ``fire extinguishing 
system'' is, therefore, retained in Sec. 25.857(c).
    Although the proposed amendment to part 25 would provide new 
standards for future transport category airplanes, it would not affect 
airplanes currently in service nor the airplanes that will be produced 
under type certificates for which application was made prior to the 
effective date of the amendment. Parts 121 and 135 would, therefore, be 
amended as well to require the Class D compartments of transport 
category airplanes type-certificated after January 1, 1958, to meet the 
standards for Class C or Class E compartments, as applicable, when they 
are used in air carrier or commercial operations. Although those 
compartments would not be reidentified as such, they would become the 
equivalent of Class C (in regard to detection and suppression) or Class 
E compartments (in regard to detection and means to limit ventilating 
air flow).
    The date January 1, 1958, was chosen so that all turbine-powered 
transport category airplanes, except for a few 1947 vintage Grumman 
Mallard amphibians and 1953-1958 vintage Convair 340s and 440s 
converted from reciprocating power, would be included. No 
reciprocating-powered transport category airplanes are known to be used 
currently in passenger service, and the few reciprocating-powered 
transport category airplanes remaining in cargo service would be 
excluded. Compliance is not proposed for those older airplanes because 
their advanced age and small numbers would make compliance impractical 
from an economic standpoint. This is consistent with the similar 
exclusions made for those airplanes from other retroactive requirements 
adopted for flammability of seat cushions (49 FR 43188, October 24, 
1984), flammability of cabin interior components (51 FR 26206, July 21, 
1986), cargo compartment liners (54 FR 7384, February 17, 1989) and 
access to passenger emergency exits (57 FR 19244, May 4, 1992). 
Nevertheless, the FAA specifically requests comments as to the 
feasibility of requiring those older airplanes to comply and the safety 
benefits likely to be realized. In the event comments indicate that a 
significant safety benefit could be realized, the FAA retains the 
option of including applicability to transport category airplanes type-
certificated prior to January 1, 1958, in the final rule.
    These proposed changes to parts 121 and 135 would pertain only to 
operators of transport category airplanes. In Notice 95-5 (60 FR 16230, 
March 29, 1995), the FAA proposed to adopt improved safety standards 
for the cargo or baggage compartments in non-transport category (e.g. 
normal and commuter category) airplanes used in scheduled passenger 
service. As noted in the preamble to the final rule (60 FR 65832, 
December 20, 1995), the FAA concurred with commenters that the present 
requirements for transport category airplanes were not entirely 
suitable for those smaller airplanes. The

[[Page 32416]]

FAA also noted that a rulemaking project to develop cargo or baggage 
compartment standards suitable for those airplanes has been initiated 
and that the changes proposed in Notice 95-5 in that regard would be 
deferred for future rulemaking. The possible need for installing 
detection and suppression systems in the cargo or baggage compartments 
of those airplanes will be addressed in conjunction with that 
rulemaking project.
    The proposed changes to parts 121 and 135 concerning Class D 
compartments would require compliance within three years after the 
effective date of the amendment. It should be noted that, with the 
possible exception of those in all-cargo airplanes, Class D 
compartments would be required to comply with existing standards for 
Class C compartments. Since this rulemaking would not involve any new 
technology and installation components are readily available, 
compliance within three years is feasible. A three-year compliance 
period would also allow sufficient time for the necessary modifications 
to be performed while each airplane is out of service for scheduled 
maintenance activity. Based on information currently available, the 
FAA, therefore, considers that a three-year compliance period would not 
impose an unreasonable burden on any operator. Nevertheless, the FAA is 
specifically requesting comments as to whether a longer compliance 
period is needed for particular operators (for example, small carriers) 
due to their particular circumstances, and retains the option of 
adopting a longer compliance period in the final rule based on such 
comments. Unless commenters submit specific information justifying a 
compliance period longer than three years, a three-year compliance 
period will be adopted as proposed.
    As noted above, the compartments in all-cargo airplanes could be 
shown to meet the standards of Class E compartments in lieu of those 
for Class C compartments. The proposed three-year compliance period is 
also considered appropriate for operators that elect to meet the 
standards for Class E compartments. As in the case of Class C 
compartment standards, the standards for Class E compartments do not 
involve any new technology and installation components are readily 
available.
    Assuming that the final rule is adopted as proposed, the FAA also 
intends to monitor operators' compliance. Such monitoring would serve 
two purposes. First, it would help to ensure that the carriers are 
converting affected compartments on a regular basis, so as to avoid 
disruptions in service, and to avoid requests for extensions near the 
end of the compliance period. Second, the FAA could inform the public 
of the operators' progress in achieving compliance.
    Therefore, this Notice proposes specific reporting requirements for 
affected operators under parts 121 and 135. A new paragraph would be 
added to Secs. 121.314 and 135.169 to require each certificate holder 
to report, on a quarterly basis, the serial numbers of the airplanes in 
that holder's fleet in which all Class D compartments have been 
retrofitted to meet Class C or E requirements, and the serial numbers 
of airplanes that have Class D compartments yet to be retrofitted. 
(Note that the proposed amendments to Secs. 121.314 and 135.169 refer 
to an initial reporting date of July 1, 1998. The FAA intends to 
require the initial reports at the beginning of the second quarter 
after the effective date of the rule; e.g., if the effective date is 
January 15, 1998, the initial reports will be required by July 1, 
1998.)
    The FAA intends to make the reported information publicly 
available, thus allowing the public to monitor the carriers' compliance 
progress. These proposed reporting requirements are subject to OMB 
approval, as required by the Paperwork Reduction Act. An information 
collection control number will be assigned for them if and when OMB 
approval is given; that number would be listed in part 11, subpart F, 
of Title 14.
    The FAA also seeks comments on what effects, if any, mandatory 
public disclosure requirements would have on the behavior of operators 
and others, given that the FAA intends to collect and make the 
information publicly available. For example would disclosure of the 
reported information result in compliance with retrofit requirements 
sooner than would otherwise be the case? If so, what effect would this 
have on the total amount and timing of benefits and costs of the rule? 
Also, what would be the best way to collect and make the information 
available, in order to enhance its usefulness to the public?
    As noted above, the new standards adopted in parts 121 and 135 for 
liners in Class C and D compartments are similar, but not identical, to 
those adopted for part 25. Section 25.855(c), as amended by Amendment 
25-60, states that ceiling and sidewall liner panels in such 
compartments must meet the test requirements of Part III of Appendix F 
of part 25. At the time the corresponding standards of parts 121 and 
135 were adopted, it was found that panels of glass fiber reinforced 
resin consistently meet or come very close to meeting the test 
requirements of Part III of Appendix F. As a result, the cost of 
replacing them with panels meeting Part III of Appendix F would not 
have been commensurate with the negligible improvement in safety that 
could be realized. Section 121.314(a) therefore permits the ceiling and 
sidewall panels to be constructed of materials that meet the test 
requirements of Part III of Appendix F or, alternatively, of glass 
fiber reinforced resin. Similarly, it was also found that panels of 
aluminum construction came close to meeting the test requirements of 
Part III of Appendix F, although not as close as those constructed of 
glass fiber reinforced resin. Section 121.314(a) therefore permits 
continued use of ceiling and sidewall panels constructed of aluminum 
provided they were approved prior to March 20, 1989. Since the FAA has 
not proposed any change in this regard, Class D compartments that are 
reconfigured to the equivalent of Class C compartments could continue 
to utilize glass fiber reinforced resin panels or, if they were 
approved prior to March 230, 1989, aluminum panels in lieu of those 
meeting the test requirements of Part III of Appendix F.
    Due to the recent adoption of part 119 and related amendments to 
part 121 (60 FR 65832, December 29, 1995), scheduled operations of 
transport category airplanes with ten to thirty passengers seats must 
be conducted under the provisions of part 121 rather than part 135. 
Nevertheless, the proposed changes to part 135 are needed because non-
scheduled operations of transport category airplanes with ten to thirty 
passenger seats may still be conducted under part 135. Scheduled, as 
well as non-scheduled, operations of transport category airplanes with 
fewer than ten passenger seats may also remain under part 135.
    The comment period for this Notice ends ninety (90) days from 
today's publication in the Federal Register. The FAA has determined 
that all of the affected Class D compartments could be retrofitted to 
meet the detection and suppression requirements for Class C or Class E 
compartments using existing technology; therefore, the FAA anticipates 
that the proposal to require Class D compartments to meet these 
requirements will not change significantly, if at all, if a final rule 
is adopted from this proposal.
    Furthermore, the FAA anticipates that, if a final rule is adopted 
from this proposal, it will be published no later than December of 
1997, with an

[[Page 32417]]

effective date in January of 1998. Assuming, also, that the final rule 
is adopted with the proposed three-year compliance period, all affected 
airplanes will be in compliance no later than January of 2001.

Halon Considerations

    As proposed in this notice, most Class D compartments would, in 
essence, become Class C compartments. Operators of all-cargo airplanes 
would have the option of converting their Class D compartments to Class 
E compartments; however, operators of passenger airplanes would have to 
convert their Class D compartments to meet the requirements of Class C. 
Although they were not previously required to have any means of fire 
extinguishment, the Class D compartments in passenger airplanes would 
have to have approved built-in fire extinguishing systems installed as 
required by Sec. 25.857(c)(2). Currently the most effective and most 
commonly used extinguishing agent is a halogenated hydrocarbon known as 
halon.
    Although reserve supplies of halon are currently available, the 
manufacture of additional halon is restricted under the Montreal 
Protocol, an international agreement to phase out production of ozone-
depleting substances, including halon. The Montreal Protocol, in 
existence since 1987, prohibits the manufacture or import of new halon 
in all developed countries (including the United States) as of January 
1, 1994, and will extend this prohibition to developing countries in 
the future. At this time, there is no restriction on the use of 
existing supplies of halon manufactured prior to 1994.
    Some operators have expressed concern that they would be required 
to install suppression systems which would, as a matter of 
practicality, utilize halon, then be required by the FAA or another 
government agency to replace those suppression systems with systems 
that do not utilize halon. The FAA would not do so for two reasons. 
First, halon has been shown to be an effective suppression agent. The 
FAA would, therefore, not require its replacement due to safety 
considerations. Second, the FAA would not require its replacement due 
to environmental considerations because the FAA lacks the statutory 
authority to do so in any event. The federal agency that would have 
that authority is the Environmental Protection Agency (EPA).
    The EPA is responsible for the regulation of halons in accordance 
with the Montreal Protocol and the requirements and authority of 
Sections 602 and 604 of Title VI of the Clean Air Act. The EPA has 
advised in its letter of May 8, 1997, that it does not intend to ban 
the use of halon in installed fire suppression systems for the life of 
the airplanes, that it can support the use of stockpiled halons to 
retrofit aircraft holds, and that it can support these policies in 
international negotiations related to aircraft or environmental 
matters. A copy of this letter has been placed in the docket for 
examination by interested persons. Nevertheless, the EPA support for 
this proposed rulemaking is conditional on airline and aircraft 
industry support of on-going efforts to develop suitable alternatives 
for use in future aircraft, and on FAA's accelerated efforts to develop 
criteria for certification of alternatives, as described more fully 
below.
    In this regard, the FAA has participated in an extensive program to 
develop criteria on which to evaluate possible alternatives. Although 
initially proposed by the FAA, this is an international program with 
active participation by the aviation industry and the regulatory 
authorities in Europe and Canada. It must be emphasized that the work 
of this group, which is known as the International Halon Replacement 
Working Group, is to participate in the research and development of 
alternative agents and systems--not to select specific agents to 
replace halons. The FAA has accelerated development of criteria for 
certification of alternatives and is committed to expeditious review 
and certification of alternatives as they are developed.
    The objective of this program is to develop certification criteria 
for approval of alternative agents and systems. Such alternatives must, 
of course, have satisfactory environmental characteristics, such as 
reduced ozone depletion potential, global warming potential and 
atmospheric lifetime. In order to maintain the excellent record of in-
flight fire safety that exists today, new agents and systems must 
provide extinguishing and suppression performance equal to or better 
than the halons. In this regard, the development of minimum performance 
standards for alternative agents and systems in cargo or baggage 
compartments has focused on four critical threats--cargo container 
fires, bulk-loaded luggage fires, surface-burning fires and fires in 
luggage containing aerosol cans.
    In addition to performing their intended function of suppressing or 
extinguishing fires and having satisfactory environmental 
characteristics, alternative agents and systems used in airplanes must 
have certain other characteristics that may not be significant for non-
aircraft usage. They, of course, must not present a health hazard 
during normal operations to persons working within the compartments or 
animals being shipped in the compartments. Due to the proximity of the 
occupants of airplanes to the cargo or baggage compartments, the 
cumulative toxicology effect of the agents, their pyrolytic breakdown 
products and the by-products of combustion must not pose an 
unacceptable health hazard when a fire does occur. They must be non-
corrosive and otherwise compatible with aircraft materials. Discharge 
of the agent must leave a minimum of residue that can be safely cleaned 
up. Finally, such alternative agents and systems must be relatively low 
in weight for economical use in airplanes.
    One very promising alternative is the use of a waterspray system. 
The FAA has conducted a very comprehensive program to develop cabin 
waterspray systems as a means of affording occupants more time to 
escape a post-crash cabin fire. Although the cost of a waterspray 
system serving only the cabin presently outweighs the likely benefits, 
it appears that benefits of a waterspray system that could serve as the 
extinguishing agent in either a cargo or baggage compartment fire, or 
in a cabin fire, would outweigh the costs of the system.
    Since the future availability of halon is uncertain, the FAA 
specifically invites comments concerning the following:
    1. The cost, feasibility and availability of halon for use as the 
extinguishing agent in former Class D compartments that would be 
reconfigured to meet the requirements of Class C as a result of this 
proposed rulemaking;
    2. The cost, feasibility and availability of waterspray systems 
that could provide protection from fires occurring in cargo or baggage 
compartments as well as in the cabin; and
    3. The cost, feasibility and availability of other possible 
alternative agents.

Regulatory Evaluation

    Proposed changes to Federal regulations must undergo several 
economic analyses. First, Executive Order 12866 directs that each 
Federal agency shall propose or adopt a regulation only upon a reasoned 
determination that the benefits of the intended regulation justify its 
costs. Second, the Regulatory Flexibility Act of 1980 requires agencies 
to analyze the economic effect of regulatory changes on small entities. 
Third, the Office of Management and Budget directs agencies to assess 
the effects of regulatory changes on international

[[Page 32418]]

trade. In conducting these analyses, the FAA has determined that this 
rule: (1) Would generate benefits that justify its costs and is a 
``significant regulatory action'' as defined by Executive Order 12866; 
and (2) would have a significant impact on a substantial number of 
small entities; and (3) would not constitute a barrier to international 
trade. The FAA has also determined that this rule is ``significant'' 
according to DOT Regulatory Polices and Procedures (44 FR 11034; 
February 26, 1979) because there has been considerable public interest 
in this subject. These analyses, available in the docket, are 
summarized below.

Regulatory Evaluation Summary

    This analysis separately considers newly-manufactured airplanes and 
in-service airplanes. There are 20 transport-category airplane models 
operating under 14 CFR parts 121 or 135 that have Class D compartments. 
It is assumed that a requirement to retroactively install detection and 
suppression systems in Class D compartments would become effective on 
January 1, 1998. The rule would allow three years for compliance; 
therefore, airplanes that are expected to be permanently retired from 
service on or before December 31, 2001, are omitted from the analysis. 
FAA estimates that 2,994 passenger airplanes and 321 all-cargo 
airplanes would be affected by the proposed rule. These estimates are 
based on an inventory compiled by the FAA's National Aviation Safety 
Data Analysis Center (NASDAC) from airplane-specific registry and 
insurance records.
    On December 12, 1996, the Air Transport Association (ATA), joined 
by Vice President Gore, formally announced that its membership would 
voluntarily install fire detection systems in Class D cargo or baggage 
compartments. (The ATA is a trade organization representing the major 
airlines in the U.S.) ATA's announcement raised an important question--
would this voluntary action render part of the proposed rule moot? That 
is, are the incremental benefits of installing fire-suppression systems 
in airplanes in which detection systems have already been installed on 
a voluntary basis sufficient to justify the additional cost of such 
suppression systems? The FAA finds that, in fact, the benefits of the 
rule exceed its costs even after taking into account the effects of 
ATA's initiative. Some or all of the important public interests 
underpinning the FAA's proposal may have motivated the ATA to announce 
on May 14, 1997, the commitment of its membership to install both 
detection and suppression systems in passenger-carrying airplanes.

Cost Estimates

    Cost estimates consider: (1) the costs associated with submitting 
compliance reports, (2) certification expenses including one-time 
equipment and tooling costs, (3) fire detection and suppression 
equipment and installation costs, and (4) variable operating costs 
(fuel costs, maintenance and inspection costs, weight off-load costs, 
and the costs associated with unnecessary diversions initiated because 
of false alarms). In addition, it is assumed that Class D compartments 
in all-cargo airplanes would be converted to E compartments which do 
not require the installation of active suppression systems.
    The proposal would require each affected operator to submit a 
quarterly report listing the serial numbers of those airplanes in its 
fleet that are in compliance with the provisions of the rule and those 
that are not in compliance. One major carrier stated that, since 
records of modifications of this scale are computerized, the reporting 
requirement would involve less than one-half of one work hour. 
Initially, however, reports may take additional time to generate as 
carriers establish procedures, forms, etc. Also, records may not be 
computerized for smaller carriers. Thus, FAA conservatively estimates 
that, on average, the rule would require two additional work hours per 
quarter for each of the approximately 130 affected carriers. Assuming 
that each carrier will file 11 reports during the three year compliance 
period and that the fully burdened hourly compensation rate is $65, the 
estimated nominal cost of this provision to the entire industry is 
approximately $186,000 or $151,000 at present value (printing, postage, 
and other miscellaneous costs are assumed negligible).
    The FAA would also incur additional costs as a result of this 
reporting requirement. This analysis conservatively assumes that each 
of approximately 90 Flight Standards District Offices (FSDO) would, on 
average, spend approximately one-half of one work hour per quarter 
processing air carrier reports (some would spend no time, some 
considerably more than one-half hour). Also, approximately 20 hours per 
quarter would be required at FAA headquarters to tabulate these 
reports. Assuming the fully burdened hourly compensation rate is $38, 
the estimated nominal cost of this provision to FAA is approximately 
$27,000 or $22,000 at present value (data transmission costs between 
FAA headquarters and each of the FSDO's is assumed negligible).
    Type design approval of the detection and suppression systems would 
be required for all airplane models affected by the proposal. Type 
design approval would be in the form of a supplemental type certificate 
(STC) issued to an applicant other than the manufacturer; or, in the 
case of the manufacturer, either an STC or an FAA-approved type-design 
change. (The requirements for obtaining FAA approval are the same in 
either case.) The FAA assumes that type-design approval would be 
required for all airplane models affected by the proposed rule. Certain 
models would require a separate type-certification program for each 
different variant, while in other cases, all variants would be 
sufficiently similar that type-design approval could be granted for all 
variants following only one type-certification program. In some 
instances, an alternate Class C compartment configuration has already 
been FAA-approved. For those models or variants, no further type-
certification effort would be required.
    The cost of a type-certification program of this nature costs 
ranges from $315,000 to $1.8 million depending on the airplane model. 
In principle, no more than one type-certification program would be 
needed per model or variant; since operators could elect to utilize the 
same detection and suppression system installations on all affected 
airplanes of that particular type. If additional entities obtain 
separate type-design approval for a given model or variant, they would 
do so for economic gain, not as a result of an FAA requirement to do 
so. Therefore, the analysis assumes the minimum number of type-
certification programs theoretically necessary to accomplish the 
conversions.
    Detection-suppression system and installation cost estimates 
postulate that compartments would be fitted with a system of optical 
smoke detectors (configured to give indication of a fire within one 
minute) and a halon suppression system. The analysis further assumes a 
quantity of halon that would provide: (1) an initial ``knockdown'' 
discharge, and (2) the capability subsequently to maintain a 3 percent 
halon concentration for one hour. This is consistent with the standards 
currently in effect for Class C compartments.
    Although the U.S. bans the import of newly-produced halon, 
sufficient quantities of recycled halon are assumed to be available to 
meet an initial demand to retrofit the affected

[[Page 32419]]

fleet. The cost of halon has risen from approximately $2 per pound 
before production was banned to $20 per pound currently. This analysis 
assumes that halon used in a retrofit would be available at $20 per 
pound. Nominal equipment and installation unit (i.e. each airplane) 
costs range from $13,000 to $101,000 depending on the airplane model.
    Although the time to retrofit could be substantial, especially for 
airplanes with three Class D compartments, industry representatives 
state that conversions could be accomplished during a C-check, a 
scheduled maintenance check that occurs about once a year. C-checks are 
typically accomplished over a four- to five-day period. Conversions 
conducted concurrent with a C-check could reduce labor hours by as much 
as 30 percent, because many areas of the airplane are easily 
accessible. Because most operators would likely perform retrofits 
during C-checks, this analysis attributes no foregone revenues due to 
downtime (i.e., time out-of-service) associated with these conversions. 
Nevertheless, the FAA seeks comments as to whether there are 
circumstances under which the necessary retrofits could not, or would 
not, be performed concurrently with a C-check. If so, how long would 
the airplane in question need to be out of service? Are there 
circumstances under which these installations would necessitate 
extending the normal duration of a C-check? If so, how many additional 
hours or days would this take?
    Depending on the airplane model and its configuration, installing 
fire suppression and detection systems would add between 7 and 300 
pounds to the empty weight of an airplane. This weight, in turn, would 
affect fuel consumption. Incremental fuel consumption costs were 
estimated for each airplane model based on the weight of additional 
equipment and suppression agent required, statistical estimates of the 
change in fuel consumption as a function of incremental weight by 
airplane type, and estimates of annual flight hours by airplane 
model.Annual per-airplane incremental fuel consumption estimates range 
from $50 to $4,900 depending on the airplane model.
    Inspection and maintenance of fire detection and suppression 
systems would include: (1) a leak check; (2) a visual inspection of the 
system; (3) a sensor test; and (4) a hydrostatic check of the fire 
bottles. The first three checks could be accomplished at each C-check, 
i.e., about once per year. A hydrostatic check would involve removing 
and replacing the fire bottle and would occur once every five years. 
The bottle would be returned to the halon provider where it would be 
recharged and checked for leaks.
    Six work-hours at a burdened hourly rate of $60 would be required 
to conduct a leak check of the system of each compartment. A visual 
inspection of the system would require 1.5 hours per compartment at $60 
per hour. Checking the sensors would require about one hour per 
compartment. It would take two mechanics one hour at a burdened hourly 
rate of $60 to remove and replace a fire bottle. Fire-bottle vendors 
typically charge between $600 and $1,000, including shipping, to 
perform a hydrostatic test and recharge the bottles, irrespective of 
the size of the bottle. Annual unit maintenance and inspection costs, 
therefore, range from $700 to $2,100 depending on the airplane model.
    Under certain combinations of conditions, some departures might be 
weight-constrained. In those cases, the additional weight of the fire 
detection and suppression systems would require an operator to off-load 
passengers or cargo. The cost of this off-load penalty is measured by 
estimating the number of displaced passengers or the amount of 
displaced cargo that could not be accommodated on another flight by the 
same or competing airline. (On the basis of a statistical analysis of 
load factors and unaccommodated demand, the FAA estimates that 5 
percent of the departures would be fully booked. Generally, most of 
these flights would not be weight constrained, but this figure is a 
conservative assumption.) Specifically, this analysis assumes that: (1) 
On average, approximately 5 percent of the departures would be 
affected; and (2) 88% of the displaced load would be placed on another 
flight of the same carrier or on a competing carrier. The cost of 
unaccommodated off-load--approximately $0.30 per pound--is a weighted 
average of passenger and cargo revenue derived from revenue, 
enplanement, and freight data collected by the Department of 
Transportation's Office of Airline Statistics. Annual unit off-load 
penalties range from $30 to $800 depending on the airplane model.
    Operators would also incur costs associated with flight diversions 
caused by false fire warnings. Since the probability of a fire is 
smaller than the reliability level of fire or smoke detectors, most 
alarms will be false. Costs include incremental airplane operating 
costs incurred during the diversion and passenger costs. Based on a 
recent FAA study of Service Difficulty Reports (SDR), proprietary 
aircraft operating data, and information from airborne fire detection 
equipment manufactures, the FAA estimates that the frequency of false 
alarms is approximately 44 per million departures. In the absence of 
more detailed information, this analysis makes the conservative 
assumption that all false alarms result in a diversion. Annual 
diversion costs per airplane range from $60 to $2,800 depending on 
airplane type.
    Based on the above, the FAA estimates total life-cycle costs for 
the retrofitted fleet in nominal terms are approximately $296 million, 
or $194 million at present value. For a newly-manufactured airplane 
delivered to an ATA carrier, the rule would increase life-cycle costs 
for an average affected airplane by approximately $110,000 in nominal 
terms, or $60,000 at present value. Unit lifecycle costs for a newly-
manufactured airplane delivered to a non-ATA carrier would increase by 
approximately $179,000, or $100,000 at present value.
    Based on these estimates, the FAA does not consider the effects of 
this rule sufficient to trigger the requirements of the Unfunded 
Mandates Reform Act or to be a ``major'' rulemaking for the purposes of 
the Congressional review requirements under the Small Business 
Regulatory Enforcement Fairness Act. The FAA requests comments on its 
cost estimates with respect to those statutes.

Benefits Estimates

    The benefits of detection and suppression systems depend on the 
degree to which the systems enable an airplane to avert a catastrophic 
accident in the event a fire occurs in a cargo or baggage compartment. 
Measuring this benefit, however, is problematic since it is determined 
not only by the relative fire-protection capabilities of Class C and 
Class D compartments, but on the probability that a fire will occur. 
Amendments to regulations--e.g. restrictions on the transportation of 
hazardous materials and more stringent burn-through requirements for 
compartment liners--would also impinge on this analysis. (It should be 
noted, however, that the improved standards for liners apply equally to 
both Class C and Class D compartments.)
    The expected (future) rate of fires occurring in cargo or baggage 
compartments is estimated using historical accident and incident data 
from the National Transportation Safety Board (NTSB), FAA, insurance 
underwriters, and foreign aviation authorities. These records show that 
during the 20-year period between 1977 and 1996, there were 19 fires 
reported

[[Page 32420]]

as having occurred worldwide in Class D and Class C compartments 
involving transport category airplanes while used in commercial 
service. During this period, air-carriers worldwide (excluding domestic 
operations within the former Soviet Union, the Russian Federation, and 
the Commonwealth of Independent States) accumulated approximately 224.5 
million departures in transport category airplanes having Class C or 
Class D compartments. The event rate for fires occurring in Class D and 
Class C compartments is, therefore, approximately 0.085 per million 
departures.
    It must be noted that the event rate of 0.085 per million 
departures is based, for the most part, on service experience that 
occurred when consumer aerosol cans contained inert propellants. As 
described above under Background, the current use of highly-flammable 
propellants in consumer aerosol cans presents an additional hazard.
    The available evidence shows that in the majority of incidents, 
Class D compartments successfully contain fires. Of the inflight fires 
occurring in Class D compartments, only four were reported to have 
resulted in casualties or substantial damage to the airplane. A precise 
estimate of the likelihood of injury or airplane damage in the event a 
fire occurs in a Class D compartment is difficult to compute, however, 
owing to the limitations of accident and incident information. In many 
cases, necessary details had to be estimated. Where the post-event 
condition of the airplane is unknown, it is assumed that there was no 
damage. Where fatalities and injuries are unreported, it is assumed 
that there were no casualties. Where necessary, the number of occupants 
is estimated by applying the average load factor for that year by the 
average passenger capacity for a given airplane model.
    The expected reduction in the proportion of occupants fatally 
injured in an accident resulting from a fire occurring in a Class D 
compartment is estimated as the ratio of fatalities to total occupants. 
Of the 1,411 individuals involved in the accidents cited above, 523 
were fatally injured, representing approximately 37% of occupants. In 
the case of all-cargo airplanes, the expected life-saving benefit is 
assumed to be zero.
    Applying the risk reduction estimate above to airplane-specific 
departure, capacity, and load factor information (and using the 
Department of Transportation's official value of a fatality averted--
$2.7 million), FAA estimates that the rule would yield benefits of 
approximately $458 million over the life of the affected in-service 
fleet (or approximately $228 million at present value).
    For a representative newly-manufactured airplane delivered to an 
ATA carrier, the FAA estimates that the rule would yield a life-cycle 
benefit of $280,000 (or $94,000 at present value). For a newly-
manufactured airplane delivered to a non-ATA carrier, FAA estimates 
that the rule would yield a life-cycle benefit of $340,000 (or $115,000 
at present value).
    In view of the above, the FAA finds that the benefits of the rule 
would outweigh its costs. Specifically, for the affected in-service 
fleet, discounted benefits would exceed costs by a factor of 
approximately 1.18. For affected newly-manufactured airplanes delivered 
to ATA carriers, discounted benefits would exceed costs by a factor of 
1.57. For newly-manufactured airplanes delivered to non-ATA carriers, 
discounted benefits would exceed costs by a factor of 1.15.
    This regulatory evaluation is based on a number of assumptions 
involving past operational experience. The public is, therefore, 
specifically invited to comment on the validity of those assumptions. 
In particular, the benefits are estimated using a worldwide accident 
rate including the Saudi Arabian Lockheed L-1011 and Gulf Air Boeing 
737 accidents noted above. Do those accidents involve any factors not 
considered by the FAA that would warrant an alternative analysis based 
only on operational experience involving U.S. air carriers?
    Apart from past occurrences and the likelihood of their recurrence, 
the FAA believes that changing circumstances may introduce new hazards 
that would not be predicted by previous service experience. For 
example, as discussed above, there is now a high percentage of checked 
luggage containing aerosol cans with flammable propellants. Although no 
fatalities are known to have occurred as a result of an aerosol can 
exploding in a Class D compartment, it is apparent from tests that such 
items do pose risks that did not exist when aerosol cans contained only 
nonflammable propellants. Are there alternative approaches the FAA 
should consider in risk assessment for this and future rulemaking?
    The Department of Transportation is also preparing rulemaking that 
would place additional restrictions on the transport of hazardous 
materials (oxygen generators including empty canisters and oxidizers) 
by air carriers (61 FR 68955, December 30, 1996). The benefits of these 
restrictions would overlap part of the benefits associated with this 
rulemaking, i.e. the elimination of Class D cargo compartments and 
their conversion to the equivalent of Class C or Class E compartments. 
As a result of a comprehensive review of cargo fire safety options, 
however, the FAA determines that both initiatives would yield benefits 
that justify their costs. Considering both initiatives together, total 
combined discounted costs are approximately equal to the combined 
benefits for airplanes in service (assuming conservatively that 
benefits are only associated with prevented inflight fires).
    The FAA believes there are also non-quantifiable benefits contained 
in this proposal, including increased consumer confidence in the 
aviation industry due to the installation of detection and suppression 
systems. The White House Commission on Aviation Safety and Security 
recommended that the FAA include these non-quantifiable benefits in 
evaluating safety proposals. The FAA took these non-quantifiable 
benefits into consideration while formulating the proposal.

Regulatory Flexibility Analysis

    The Regulatory Flexibility Act of 1980 (RFA) was enacted by 
Congress to ensure that small entities are not unnecessarily and 
disproportionately burdened by government regulations. The RFA requires 
agencies to review rules which may have ``a significant economic impact 
on a substantial number of small entities.'' FAA Order 2100.14A, 
Regulatory Flexibility Criteria and Guidance, specifies small entity 
size and cost thresholds by Standard Industrial Classification (SIC). 
Entities potentially affected by the rule include manufacturers of 
transport category airplanes (SIC 3721), and operators of airplanes for 
hire (SIC 4511).
    There are no manufacturers of transport category airplanes that 
meet the SIC 3721 size threshold for small entities. On the basis of 
Aircraft Registry data, however, FAA estimates that 49 air carriers 
meet the size criterion for SIC 4511.
    The definition of ``significant economic impact'' varies by 
operator type. For ``type 1'' scheduled carriers, whose fleets consist 
of airplanes having a seating capacity of more than 60 passengers, the 
threshold is $123,000. For ``type 2'' carriers--which include scheduled 
carriers operating airplanes seating 60 or fewer passengers (e.g., 
commuter airlines)--the threshold is $69,000. For ``type 3'' carriers 
--including charter airlines and other passenger and cargo carriers 
providing unscheduled service--the threshold is $5,000. Annualized 
costs per airplane

[[Page 32421]]

(in 1996 dollars) are computed by amortizing the total discounted costs 
for each airplane over its expected remaining service life. Annualized 
costs per air carrier--obtained by summing the per airplane annualized 
estimates--are then compared to the thresholds above.
    FAA Order 2100.14A defines a ``substantial number of small 
entities'' as ``a number which is not less than eleven and which is 
more than one-third of the small entities subject to a proposed or 
existing rule * * *.'' This analysis finds that the proposed rulemaking 
would significantly affect 31 of the 49 small entities identified 
above--clearly, 31 is both greater than 11 and greater than one-third 
of the affected small entities. The FAA, therefore, determines that the 
proposed rule would have a significant economic impact on a substantial 
number of small entities.
    In light of the economic impact of the proposal, FAA convened a 
panel of experts--including representatives from FAA and the Department 
of Transportation's Research and Special Programs Administration 
(RSPA)--to evaluate the relative advantages and disadvantages of 
various fire prevention and protection options. These options ranged 
from relatively low-cost, purely preventative approaches (e.g. banning 
certain types of material from air transport) to mitigative approaches 
(e.g. fire detection and suppression systems). Panel participants 
specifically considered the degree to which one approach would dilute 
the benefits of other approaches.
    At the request of the FAA Administrator, consideration was also 
given to alternative fire detection and suppression system installation 
options (and various logical permutations of these options) including: 
(1) retrofit of detection systems only, (2) a requirement for detection 
systems on newly manufactured airplanes only, (3) a requirement for 
detection and suppression systems for extended overwater operations 
only, (4) retrofit of detection and suppression systems, (5) a 
requirement for detection and suppression systems on newly manufactured 
airplanes only.
    On the basis of this comprehensive analysis of policy options, the 
FAA concludes that no alternative to full detection and, for passenger-
carrying airplanes, suppression system would achieve equivalent safety 
benefits while at the same time reducing the cost impact on small 
entities.
    It is possible, however, that extending the deadline by which small 
entities must complete these retrofits could provide some cost relief. 
The FAA's preliminary analysis suggests that extending the compliance 
period is not justified for several reasons. First, the requirement as 
proposed is modest. A small operator would be required to convert up to 
nine airplanes (the small-entity threshold) within three years. Second, 
the FAA expects that the potential costs reduction would be very small. 
It is true that extending the deadline could permit a small operator to 
retire some airplanes without conversion; however, assuming the 
operator maintains the same capacity, the retired airplanes would have 
to be replaced either through purchase or lease. The replacement 
airplanes would have to incorporate detection and, in the case of 
passenger-carrying airplanes, suppression. Theoretically, then, the 
cost savings would equal the return on capital (required to finance the 
retrofits) that would accrue during the short time that operators could 
delay conversions. Finally, this small savings must be weighed against 
the increased length of time that airplane occupants would be exposed 
to greater fire hazards. For example, when a fire occurs in a Class D 
compartment, it is irrelevant, insofar as the potential safety hazards 
are concerned, whether the airplane is operated by a ``small entity'' 
or any other entity that is not ``small.''
    Nevertheless, the FAA invites comments on the impacts of cost and 
benefits associated with extending the compliance time for small 
entities.

International Trade Impact Assessment

    Recognizing the regulations that are nominally domestic in nature 
often affect international trade, the Office of Management and Budget 
directs Federal Agencies to assess whether or not a rule or regulation 
would affect any trade-sensitive activity.
    The proposed rule could potentially affect international trade by 
burdening domestic manufacturers and air carriers with requirements 
that are not applicable to their foreign competitors, and thereby 
increase the relative price of domestically-produced goods and air 
travel provided by domestic operators.
    The FAA holds, however, that the proposed rule would have a 
negligible impact on international trade. First, the rule would not 
establish either a competitive advantage or disadvantage for domestic 
airframe manufacturers--both domestic and foreign firms would be unable 
to sell newly-manufactured transport category airplanes with Class D 
cargo or baggage compartments in the U.S. since they would be 
ineligible for air carrier service in this country after December 31, 
2000. Second, as noted above, several major U.S. air carriers have 
already voluntarily installed detection or detection-suppression 
systems in airplanes for which there is no existing requirements to do 
so. This is also true for at least one major foreign airline. Third, 
the proposed rule would primarily affect smaller narrow-body airplanes 
that are used on domestic routes. Foreign carriers, of course, are not 
permitted to compete on domestic routes. Most airplanes used in 
international service are larger models which are already equipped with 
cargo or baggage compartment fire-detection and suppression systems. 
Finally, foreign civil aviation authorities have indicated to the FAA 
that they expect to adopt similar fire-detection and suppression 
requirements.

Federalism Implications

    The regulations proposed herein would not have a substantial direct 
effect on the states, on the relationship between the national 
government and the states, or on the distribution of power or 
responsibilities among the various levels of government. Therefore, in 
accordance with Executive Order 12612, it is determined that this 
proposal would not have significant federalism implications to warrant 
the preparation of a Federalism Assessment.

International Compatibility

    The FAA has reviewed the corresponding International Civil Aviation 
Organization regulations, where they exist, and has identified no 
differences in these proposed amendments and the foreign regulations. 
The FAA has also reviewed the Joint Airworthiness Authority Regulations 
and has discussed similarities and differences in these proposed 
amendments and the foreign regulations.

Paperwork Reduction Act

    This Notice proposes reporting requirements, which are subject to 
OMB approval, as required by the Paperwork Reduction Act of 1995. An 
information collection control number will be assigned for them if and 
when OMB approval is given. The costs and benefits of these proposed 
collection requirements are set forth in the section entitled ``Cost 
Estimates,'' above.

Regulations Affecting Interstate Aviation in Alaska

    Section 1205 of the FAA Reauthorization Act of 1996 (110 Stat. 
3213) requires the Administrator, when modifying regulations in Title 
14 of the CFR in a manner affecting intrastate aviation in Alaska, to 
consider the

[[Page 32422]]

extent to which Alaska is not served by transportation modes other than 
aviation, and to establish such regulatory distinctions as he or she 
considers appropriate. Because this proposed rule would apply to the 
operation of most transport-category airplanes under parts 121 and 135 
of Title 14, it could, if adopted, affect intrastate aviation in 
Alaska. The FAA, therefore, specifically requests comments on whether 
there is justification for applying the proposed rule differently to 
intrastate operations in Alaska.

Conclusion

    Because the proposed changes to upgrade the fire safety standards 
for cargo or baggage compartments are not expected to result in a 
substantial economic cost, the FAA has determined that this proposed 
legislation would not be major under Executive Order 12866. Because 
this is an issue which has prompted a great deal of public concern, the 
FAA has determined that this action is significant under DOT Regulatory 
Policies and Procedures (44 FR 11034; February 26, 1979). A copy of the 
regulatory evaluation prepared for this project may be examined in the 
Rules Docket or obtained from the person identified under the caption 
FOR FURTHER INFORMATION CONTACT.

List of Subjects

14 CFR Part 25

    Aircraft, Aviation safety.

14 CFR Part 121

    Aviation safety, Air carriers, Air transportation, Aircraft, 
Airplanes, Transportation.

14 CFR Part 135

    Aviation safety, Aircraft, Airplanes.

The Proposed Amendments

    Accordingly, the FAA proposes to amend the Federal Aviation 
Regulations (FAR) 14 CFR parts 25, 121, and 135 as follows:

PART 25--AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES

    1. The authority citation for part 25 is revised to read as 
follows:

    Authority: 49 USC 106(g) 40113, 44701, 44702 and 44704.
    2. Section 25.855(c) is revised to read as follows:


Sec. 25.855  Cargo or baggage compartments.

* * * * *
    (c) Ceiling and sidewall liner panels of Class C compartments must 
meet the test requirements of part III or appendix F of this part or 
other approved equivalent methods.
* * * * *


Sec. 25.857  [Amended]

    3. Section 25.857 is amended by removing and reserving paragraph 
(d).
    4. Section 25.858 is amended by revising the section heading and 
the introductory paragraph to read as follows:


Sec. 25.858  Cargo or baggage compartment smoke or fire detection 
systems.

    If certification with cargo or baggage compartment smoke or fire 
detection provisions is requested, the following must be met for each 
cargo or baggage compartment with those provisions:
* * * * *

PART 121--OPERATING REQUIREMENTS: DOMESTIC, FLAG AND SUPPLEMENTAL 
OPERATIONS

    5. The authority citation for part 121 continues to read as 
follows:
    Authority: 49 USC 106(g), 40113, 40119, 44101, 44701-44702, 
44705, 44709-44711, 44716-44717, 44722, 44901, 44903-44904, 44912, 
46105.

    6. Section 121.314 is revised to read as follows:


Sec. 121.314  Cargo and baggage compartments.

    For each transport category airplane type certificated after 
January 1, 1958:
    (a) Each Class C or Class D compartment, as defined in Sec. 25.857 
of this Chapter in effect on June 16, 1986 (see Appendix L to this 
part), that is greater than 200 cubic feet in volume must have ceiling 
and sidewall liner panels which are constructed of:
    (1) Glass fiber reinforced resin;
    (2) Materials which meet the test requirements of part 25, appendix 
F part III of this chapter; or
    (3) In the case of liner installations approved prior to March 20, 
1989, aluminum.
    (b) For compliance with paragraph (a) of this section, the term 
``liner'' includes any design feature, such as a joint or fastener, 
which would affect the capability of the liner to safely contain a 
fire.
    (c) After [insert date three years after the effective date of the 
final rule], each Class D compartment, regardless of volume, must meet 
the standards of Secs. 25.857(c) and 25.858 of this Chapter for a Class 
C compartment unless the operation is an all-cargo operation in which 
case each Class D compartment may meet the standards in Sec. 25.857(e) 
for a Class E compartment.
    (d) Reports of compliance with paragraph (c) of this section. Each 
certificate holder must submit written reports to the FAA that contain 
information about the airplanes being operated by that certificate 
holder and the holder's compliance with paragraph (c) of this section. 
A written report must be submitted to the Certificate-holding District 
Office by July 1, 1998, and at each three-month interval thereafter, 
that contains:
    (1) The serial number of each airplane in which all Class D 
compartments have been retrofitted to meet the fire detection and 
suppression requirements for Class C or the fire detection requirements 
for Class E; and
    (2) The serial number of each airplane that has at least one Class 
D compartment that has not been retrofitted.
    7. Appendix L to part 121 is amended by adding to the table an 
entry for Sec. 121.314(a) to read as follows:

Appendix L to Part 121--Type Certification Regulations Made 
Previously Effective

* * * * *

------------------------------------------------------------------------
                                      Applicable      Provisions: CFR/FR
        Part 121 section               aircraft           references    
------------------------------------------------------------------------
                                                                        
                  *        *        *        *        *                 
Sec.  121.314 (a)...............  Transport category  Class C or D cargo
                                   airplanes type      or baggage       
                                   certificated        compartment      
                                   after January 1,    definition, 14   
                                   1958.               CFR 25.857 in    
                                                       effect on June   
                                                       16, 1986, 14 CFR 
                                                       parts 1 to 59,   
                                                       revised as of    
                                                       Jan. 1, 1997, and
                                                       amended by       
                                                       Amendment 25-60, 
                                                       51 FR 18243, May 
                                                       16, 1986.        
------------------------------------------------------------------------

PART 135--OPERATING REQUIREMENTS: COMMUTER AND ON-DEMAND OPERATIONS

    8. The authority citation for part 135 continues to read as 
follows:

    Authority: 49 U.S.C. 106(g) 40113, 44701-44702, 44705, 44709, 
44711-44713, 44715-44717, 44722.

    9. Section 135.169 is amended by revising paragraph (d) 
introductory text and paragraph (d)(1); and adding new paragraphs 
(d)(3) and (e) to read as follows:

[[Page 32423]]

Sec. 135.169  Additional airworthiness requirements.

* * * * *
    (d) Cargo or baggage compartments installed in each transport 
category airplane type certificated after January 1, 1958:
    (1) Each Class C or D compartment, as defined in Sec. 25.857 of 
part 25 of this chapter in effect on June 16, 1986 (see appendix F to 
this part), greater than 200 cubic feet in volume, must have ceiling 
and sidewall panels which are constructed of:
* * * * *
    (3) After [insert a date three years after the effective date of 
the final rule], each Class D compartment, regardless of volume, must 
meet the standards of Secs. 25.857(c) and 25.858 of this chapter for a 
Class C compartment unless the operation is an all-cargo operation in 
which case each Class D compartment may meet the standards in 
Sec. 25.857(e) for a Class E compartment.
    (e) Reports of compliance with paragraph (d)(3) of this section. 
Each certificate holder must submit written reports to the FAA that 
contain information about the airplanes being operated by that 
certificate holder and the holder's compliance with paragraph (d)(3) of 
this section. A written report must be submitted to the Certificate-
holding District Office by July 1, 1998, and at each three-month 
interval thereafter, that contains:
    (1) The serial number of each airplane in which all Class D 
compartments have been retrofitted to meet the fire detection and 
suppression requirements for Class C or the fire detection requirements 
for Class E; and
    (2) The serial number of each airplane that has at least one Class 
D compartments that has not been retrofitted.
    10. A new Appendix F is added to part 135 to read as follows:

Appendix F to Part 135--Type Certification Regulations Made 
Previously Effective

    Appendix F lists regulations in this part that require compliance 
with standards contained in superseded type certification regulations 
that continue to apply to certain transport category airplanes. The 
tables set out citations to current CFR section, applicable aircraft, 
superseded type certification regulation and applicable time periods, 
and the CFR edition and Federal Register documents where the regulation 
having prior effect is found. Copies of all superseded regulations may 
be obtained at the Federal Aviation Administration Law Library, Room 
924, 800 Independence Avenue SW, Washington, DC.

------------------------------------------------------------------------
                                      Applicable      Provisions: CFR/FR
        Part 135 section               aircraft           references    
------------------------------------------------------------------------
Sec.  135.169 (d)...............  Transport category  Class C or D cargo
                                   airplanes type-     or baggage       
                                   certified after     compartment      
                                   January 1, 1958.    definition. 14   
                                                       CFR 25.857 in    
                                                       effect on June   
                                                       16, 1986, 14 CFR 
                                                       parts 1 to 59,   
                                                       revised as of    
                                                       Jan. 1, 1997, and
                                                       amended by       
                                                       Amendment 25-60, 
                                                       51 FR 18243, May 
                                                       16, 1986.        
------------------------------------------------------------------------

    Issued in Washington, D.C. on June 9, 1997.
James C. Jones,
Acting Director, Aircraft Certification Service.
[FR Doc. 97-15457 Filed 6-10-97; 1:18 pm]
BILLING CODE 4910-13-M